Click here to see the PowerPoint

Polyethylene in Space
Jonathon Ball, Kirk Norasak
Goals For the Summer
Develop an irradiation setup to imitate “space”
To test mechanical properties of UHMWPE
irradiated in “space” conditions.
To improve the Orthopod wear testing
To wear test the proton irradiated PE at Earth
Questions to Address
• What are the radiation conditions in space?
• What are conditions at different points in space?
• Why is polyethylene used in space?
• What are the uses of polyethylene in space?
• What other polymers are used in space?
• Polymers Irradiated in a Vacuum vs. Air
• Ideas for system setup to imitate polyethylene in space conditions.
• Timeline for wear testing of polyethylene samples proton-irradiated
in STP of earth.
What are the radiation conditions in space?
galactic cosmic rays
solar particle events
◦Includes protons and highly charged nuclei.
◦Includes protons from Solar Flares, and large mass releases from the sun.
87% of the particles of the GCR are protons, 12% are helium nuclei and 1%
are particles heavier than helium
Characteristics of
space radiation
proton energy range
up to several 100
up to several 1000
HZE energy range
no significant
up to several 1000
Walter Schimmerling
National Aeronautics and Space
Administration, Washington, DC
What are conditions at different points in
International Space Station-
(-157)C - 121C 0mbar pressure
(-233)C - 123C
0mbar pressure
(-153)C - 20C
7.5mbar pressure
Reentry to the atmosphere-
Why is polyethylene used in space?
• Readily available.
• The high hydrogen content allows this polymer to block
radiation neutrons.
• Can be easily made into a composite Ex.(Boron Nitride, and
Carbon nanotubes.) to improve properties such as Young's
What are the uses of polyethylene in
• The PE is used in the crew quarters on the
International Space Station. Provided 22%
reduction in radiation exposure while in the
space station.
Used in the fibers and fabrics of Space
• PE based material RXF1 was developed
to possibly build a plastic space ship to
replace the Al outer shell. 3X stronger and
2.6X lighter than Al. 50% better SPE
shielding and 15% better Cosmic ray
shielding. Increased shielding would be
necessary for a mission to Mars which is
expected to last at least 30 months.
What other polymers are used in
Mylar (PET)- Has radiation resistance
Electrical insulator
Used to make Solar Sails
Kapton - Temp range -273 to 400 C
Used for wire coating
Used as an insulator in UH Vac environment
Neoprene- Insulation (Wet suits) to regulate body temperature.
PTFE (Teflon) – Outer protection on the space suit.
Polymers Irradiated in a Vacuum vs. Air
samples that are irradiated show improved
mechanical properties.
the vacuum PTFE has shown to reduce toxic
components such as HF.
in pre-irradiation vacuum removed oxygen in the
system, thus leaving more free radicals to form crosslinks.
System setup to imitate polyethylene in
space conditions.
Vacuum package the PE and immerse it into a liquid Nitrogen
storage device. After that, place the setup into the radiation
testing area.
Questions still to be answered for the setup:
◦What is the pressure of the polyethylene while vacuum packaged?
◦What is the radiation shielding coefficient of the packaging material?
◦How to quantify the temperature of the PE immersed in the LN?
◦Does the LN have a shielding effect?
◦Is the effects due to the lack of Oxygen or the pressure the Vacuum
Timeline of Pin-on-Disk wear testing for
polyethylene that was proton-irradiated at
Earth's STP
2 weeks- machining time on pins, receiving new SS buttons, new circle
Begin Testing June 27
◦ 2 days per 10 km
 Every MWF begin new runs of 10km
 Run samples for 40km stopping every 10km to determine wear
 Focus on 0Gy and 35Gy samples of 1020 PE and 1020E PE for a total
of 4 sample sets.
◦ Using the developed schedule, testing on the 4 different sets would be
completed August 3.
(1) Archodoulaki, V. -.; Koch, T.; Rodriguez, A.; Seidler, S. Influence of Different Sterilization Procedures on the
Morphological Parameters and Mechanical Properties of Ultra-High-Molecular-Weight Polyethylene. J Appl
Polym Sci 2011, 120, 1875-1884.
(2) Banford, H. M.; Yufen, W.; Tedford, D. J.; Given, M. J. The dielectric response of polyimide to combined
radiation, vacuum and thermal aging. IEEE 1995 Annual Report.Conference on Electrical Insulation and Dielectric
Phenomena (Cat.No.95CH35842) 1995, 239; 239-242; 242.
(3) Brichard, B.; Ooms, H.; Starckx, J.; Fernandez, A. F.; van Uffelen, M.; Berghmans, F. SCK-CEN gamma
irradiation facilities for radiation testing in high-vacuum conditions. Proceedings of the 7th European Conference
on Radiation and its Effects on Components and Systems - RADECS 2003 (IEEE Cat.No.03TH8776) 2004, 513;
513-515; 515.
(4) Burroughs, B. R.; Blanchet, T. A. The effect of pre-irradiation vacuum storage on the oxidation and wear of
radiation sterilized UHMWPE. Wear 2006, 261, 1277-1284.
(5) Chiggiato, P.; Kersevan, R. Synchrotron radiation-induced desorption from a NEG-coated vacuum chamber.
Vacuum 2001, 60, 67-72.
(6) Guetersloh, S.; Zeitlin, C.; Heilbronn, L.; Miller, J.; Komiyama, T.; Fukumura, A.; Iwata, Y.; Murakami, T.;
Bhattacharya, M. Polyethylene as a radiation shielding standard in simulated cosmic-ray environments. Nuclear
Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 2006, 252,
(7) Huot, J. C.; Van Citters, D. W.; Currier, J. H.; Collier, J. P. The effect of radiation dose on the tensile and impact
toughness of highly cross-linked and remelted ultrahigh-molecular weight polyethylenes. J. Biomed. Mater. Res.
2011, 97B, 327-333.
References cont.
(8) Korenev, S. Method of radiation degradation of PTFE under vacuum conditions. Radiat. Phys. Chem. 2004, 71,
(9) Korenev, S. Method of radiation degradation of PTFE under vacuum conditions. Radiat. Phys. Chem. 2004, 71,
(10) Premnath,V.; Harris, W. H.; Jasty, M.; Merrill, E. W. Gamma sterilization of UHMWPE articular implants: An
analysis of the oxidation problem. Biomaterials 1996, 17, 1741-1753.
(11) Sarcinelli, L.; Valenza, A.; Spadaro, G. Inverse response of polypropylene to gamma radiation under vacuum.
Polymer 1997, 38, 2307-2313.
(12) Schimmerling,W. Overview of NASA's space radiation research program. Gravit Space Biol Bull 2003, 16, 510.
(13) Shavers, M. R.; Zapp, N.; Barber, R. E.; Wilson, J. W.; Qualls, G.; Toupes, L.; Ramsey, S.;Vinci,V.; Smith, G.;
Cucinotta, F. A. Implementation of ALARA radiation protection on the ISS through polyethylene shielding
augmentation of the Service Module Crew Quarters. Advances in Space Research 2004, 34, 1333-1337.
(14) Stephens, C. P.; Benson, R. S.; Esther Martinez-Pardo, M.; Barker, E. D.; Walker, J. B.; Stephens,T. P. The effect
of dose rate on the crystalline lamellar thickness distribution in gamma-radiation of UHMWPE. Nuclear
Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 2005, 236,
(15) Zhong,W. H.; Miller, J. In In Reactive nano-epoxy matrix and the UHMWPE fiber composites for cosmic radiation
shielding; International Conference on Smart Materials and Nanotechnology in Engineering, July 1, 2007 July 4; SPIE: Harbin, China, 2007;Vol. 6423, pp SPIE; Harbin Institute of Technology, China.
(16) Zhong,W. H.; Sui, G.; Jana, S.; Miller, J. Cosmic radiation shielding tests for UHMWPE fiber/nano-epoxy
composites. Composites Sci.Technol. 2009, 69, 2093-7.
References cont.
(17) Ask A Scientist. (accessed
June 6, 2011).
(18) What is the temperature on the Moon? (accessed June
6, 2011).
(19) Mars Facts. (accessed June 6, 2011).
(20) Barry, P. L. Plastic Spaceships. (accessed June 6, 2011).
(21) Pline, A. Exploration: Moon, Mars, and Beyond. (accessed June 6, 2011).
(22) Price, S.; Phillips, T.; Knier, G. Staying Cool on the ISS. (accessed June 6, 2011).

similar documents